Abstract

A cardiotoxin-like basic polypeptide from the venom of Naja naja atra is homologous to cardiotoxins from the same venom, but much less toxic. To determine if it acts like the cardiotoxins its depolarizing ability was measured. It was about 10 times less potent than the cardiotoxins. Five amino acids are conserved in the sequences studied, on the exposed second and third loops of the toxin backbone. They may be part of the toxins' interactive site.